Anatase Versus Rutile: Optimizing TiO₂-Based Triboelectric Nanogenerators for Clean Energy Harvesting

Abstract

Triboelectric nanogenerators (TENGs) have emerged as a promising alternative technology for sustainable energy harvesting, which is aligning with Sustainable Development Goal 7 (SDG 7). Strategies such as optimizing material selection, modifying surface morphology, and engineering interfacial structures have been explored to enhance TENG performance. However, the role of semiconductor metal oxides in TENG applications remains relatively underexplored. In this manuscript, the role of titanium dioxide (TiO₂), particularly its rutile and anatase phases, in improving the output performance of TENGs is investigated. The fabricated TiO₂-based TENGs are systematically analyzed, revealing that rutile-phase TiO₂ demonstrated superior performance compared to anatase, with a 1.25-fold increase in voltage and a 1.16-fold increase in current. This enhancement is attributed to rutile's higher dielectric constant, improved charge mobility, and optimized surface morphology. The optimized TiO₂-based TENG achieved impressive performance metrics, including a voltage output of 500 V, a current output of 140 µA, and a power density of 8.16 W m−2, making it highly suitable for self-powered applications. The present findings underscore the viability of TiO₂-based TENGs as a scalable and efficient energy solution, paving the way for sustainable and self-powered applications.